How do breeder reactors make more fissile isotopes than they start with but typical reactors don't?
I've heard of breeding ratios, but how do reactors get a breeding ratio above 1? The only explanation I've heard is "by having a good enough neutron economy" but what parts of the reactor actually cause that to be achieved that in practice? The only thing I can think of is heavy water in CANDU reactors with typically a better breeding ratio than light water reactors, but otherwise, how do breeder reactors do it?
A mild amount of dumbing down would be appreciated, but I do know a little bit but nuclear physics. Thanks for any answers. #science